Bacteria that show resistance to decolorization by hydrochloric acid alcohol after fixed and stained with, for example, fuchsine or Crystal violet are called acid-fast bacillus, acid-fast bacillus bacteria, etc.
The acid-fast bacillus includes bacteria belonging to the genus Mycobacterium such as tuberculosis bacteria (Mycobacterium tuberculosis).
Tuberculosis is an infectious disease caused by tuberculosis bacteria. Among infectious diseases worldwide, tuberculosis is a disease of which the largest number of people died as a single infection. In recent years, multidrug-resistant tuberculosis (MDR-TB) bacteria and extensively drug-resistant tuberculosis (XDR-TB) bacteria have been detected in the tuberculosis bacteria, raising a serious problem.
Hitherto, caprazamycins or derivatives thereof have been found as compounds having excellent antibacterial activity against acid-fast bacillus (see, for example, PTLs 1 to 4).
Among these proposed compounds, for example, CPZEN-45, which is a derivative of caprazamycin, has been found to have excellent antibacterial activity against multidrug-resistant tuberculosis (MDR-TB) bacteria and extensively drug-resistant tuberculosis (XDR-TB) bacteria.
Under such circumstances, studies have actively been made to develop a therapeutic drug against tuberculosis caused by tuberculosis bacteria included in acid-fast bacillus, and keen demand has arisen for provision of a more effective therapeutic drug.